On all platforms, Firefox has gained VP9 video decoding. For those who don’t know, VP9 is the successor to VP8, both of which fall under Google’s WebM project of freeing Web codecs from royalty constraints.

Desktop

While this isn’t a major release, Firefox 28 does have specific changes worth noting for both Windows and OS X. The former has lost support for Metro while the latter has gained Notification Center support for Web notifications.